Method for locating and sealing pipe leaks



J. A. ZURBRIGEN ETAL Original Filed April 1, 1959 II/I lI/l METHOD FORLOCATING AND SEALING PIPE LEAKS Feb. 9, 1965 United States Patent 12Claims. c1. 138-97 This applicatiomiwhich is a division of priorapplication Serial No. 803,442, filed April 1, 1959 for Method andMechanism for the Internal Sealing of a Pipe Leak, relates to a methodfor locating and sealing a pipe leak such as may be encountered at ajoint between sewer pipe sections.

Frequently a pipe such as a sewer pipe develops leaks, particularly atthe joints between the pipe sections. Prior to this invention, the leakwas located, one or more holes were drilled down to the pipe joint wherethe leak occurred and the joint was then filled with material such ascement from the exterior of the pipe. This has been an expensive andcomplicated solution to the problem as compared to the inventiondisclosed herein, in which the detection of the leak and the plugging ofthe leak are accomplished internally of the pipe without any exteriorholes drilled down to the pipe joint.

One of the objects of the invention is to provide a method forinternally sealing a pipe leak by a means of a packer with an associatedtelevision camera comprising the steps of moving the packer along thepipe until a leak is detected and a target located a fixed distance fromthe packer is at the leak, advancing the packer an amount equal to saidfixed distance to place the packer at the leak, isolating the leak fromthe remainder of the pipe, and injecting a settable material into saidleak to close ofr the leak.

Another object of the invention is to provide a method for internallysealing a pipe leak by means of a packer with associated means fordetecting the location of the leak, means for injecting a leak pluggingmaterial into the leak including injection means positionable adjacentthe leak, and means for isolating the area of the pipe having the leakfrom the remainder of the pipe including an inflatable skin on thepacker movable under fluid pressure radially outwardly intocircumferential contact with the pipe at either side of the injectionpoint.

The invention is illustrated in the accompanying drawings in which:

FIG. 1 is a vertical section through a pipe and the sealing mechanismwith the sealing mechanism shown in leak sighting position and withparts of the sealing mechanism shown diagrammatically;

FIG. 2 is a view similar to FIG. 1 showing the sealing mechanism at thelocation of the leak; and

FIG. 3 is a diagrammatic vertical section on an enlarged scale of avalve mechanism carried by the sealing mechanism.

As shown in the drawings, a length of pipe such as a sewer pipe iscomposed of pipe sections 19, 11, and 12 which interfit at joints 13 and14. Normally these joints are sealed in a suitable manner such as by apacking 15; however, leaks can develop in them. When the pipe isdisposed in certain types of soil or locations, water can seep or leakinto the pipe through an inadequately sealed joint between pipesections.

In order to seal the leaking pipe joint, a packer, indicated generallyat in FIGS. 1 and 2, is provided. The packer 20 embodies a generallycylindrical casing 21 of a size somewhat less than the pipes interiordiameter so as to be movable within the pipe. The packer has tow3,.l@8,9il9 Patented Feb. 9, i965 ice cables 22 and 23 connected toopposite ends of the casing through connectors 24 and 25 attached to thecasing. The cables extend along the pipe and pass upwardly to above thesurface of the ground at spaced locations, whereby one cable may be paidout and the other taken in to result in movement of the packer along thepipe. The packer has spaced pairs of skids 21a and 2112 which supportthe packer for sliding movement.

Means are provided for detecting a leak in the pipe comprising acommercially available closed circuit television system in which atelevision camera 26 and associated lights are carried by the packercasing 21 with the camera directed toward a target in the form of a ball27 attached to cable 23 a fixed distance ahead of the packer 29. Thetelevision cable 23 extending therefrom leads to an operators locationabove ground where a television receiver indicates to an operator thecondition of the pipe interior as seen by the camera 26. It will thus beseen that as the cables 22 and 23 are operated to move the packer 29along the pipe, the camera 26 will detect the location of a leak andsince the camera sights the ball 27, it is possible as a result ofimpingement of water on the ball 27 to locate the packer it) in aposition wherein theball 27 is adjacent the leak.

The packer 29 has an injection point, indicated generally at 30, throughwhich material may be injected into the leak for sealing thereof. Thisinjection point is a fixed distance from ball 27. Thus an operator,after ball 27 has been sighted at the leak, knows exactly the distancethat the packer 243 must be advanced to place the injection point 36over the leak in the position shown in PEG. 2.

The packer 29 has means for isolating the area of the pipe having a leakfrom the remainder thereof comprising an air impervious cylindrical skin31, made of rubber or the like, which surrounds the casing .21 and whichis clamped at its ends to the casing by rings 32 and 33. Means fordirecting compressed air between the casing 21'. and the skin 31includes a supply pipe 34; which extends through an opening 35 in thecasing 21. As shown in FIG. 2, the expansion of the skin 31 results incontact with the inner periphery of the pipe and the skin readily adaptsto out of round pipes as well as out of line joints.

A void forms in the skin at the injection point 3% when the skin isexpanded, this being due to the construction at the injection point 3%This construction includes an outlet pipe Ella passing through thecasing 21 having an exterior end which is threaded and which extendsbeyond the skin 3i. A plate 37 threads onto the end of the outlet pipe30a and is of a diameter sufiicient to hold a part of the skin againstexpansion. This plate is tightened sufiiciently to maintain the air sealbetween the skin 31 and the exterior of the casing 21.

With the packer located and the skin 31 expanded as shown in FIG. 2,means provided for the purpose are em ployed to determine the acceptanceof fluid through the leak. They comprise a valve indicated generally at49 and a fluid line 41 leading from a position above ground. Water isdirected to outlet pipe 30a through the line 41 and the valve 4d to theinjection point 39. The line 41 and valve 49, along with the outlet pipe3% and injection point 36, also comprise means for injecting a leakplugging material into the pipe joint 1d after the test for fluidacceptance, this material being indicated at St The leak pluggingmaterial is desirably one which is in a fluid state when initially mixedso that it can readily pass through the line ill from above ground tothe injection point 30 and then with a minimum amount of time will setto plug the leak in the pipe joint. One example of a suitablepolymerizing material is the following, with percentages by weight basedon a full measure of water: (1) Acrylamide methylene bis acrylamide-'l2%by weight, (2) Ammonium persulfate.5%

by weight, (3) Nitrilotrispropionamide-.8%, and the balance water. Thismixture may also have an addition of clays or abestos fibers or othermiscellaneous fillers.

After plugging of the leak with the plugging material, the valve asholds the plugging material behind the injection point 3ft until theplugging material has set. Thereafter the skin 31 is deflated bypermitting the air to escape through the line Water may then be forcedthrough the line 41 and the valve 4% to blow the injection point 39clean and the packer is then readyfor the next leak. A suitable valve isshown in PEG. 3 in which the lines 41 and 42 connect to a valve casing45 and. outlet lines a and 43 also connect to the casing. A valve stern4a? is movably mounted within the casing and when positioned as shown inFIG. 3 connects the line 43, to the injection point 30. The valve stem46 may shift toward.

the right, blacking off outlet line 39a and connecting the line 41 withthe outlet line 43.

The valve stem 4-5 is connected to a piston 47 mounted in a cylinder 48and the piston is urged toward the left, as viewed in FIG. 3, by aspring 49 whereby the valve stem 46 is normally positioned as shown inthe figure. When Water or other liquids enters through the line 42, thepiston 47 is shifted toward the right against the spring 49 to shift thevalve stem 46 to the right and thus place the line 41 in communicationwith the outlet line 43 and close off the outlet line 3th: to theinjection point 38.

It is believed that from the foregoing description the method will beentirely clear; however, it may be briefly summarized as follows. Thepacker is drawn through the pipe with the cables 22 and 23 until a leakis observed by the camera 25, the ball 27 is positioned at the leak, andthe measurement is then taken. The packer is then moved ahead a distanceequal to the distance between the ball 27 and injection point to locatethe injection point 3! directly over the leak. Compressed air is thenpassed through the line 34 to expand the skin 31 into close contact withthe pipe on either side of the leak.

After the skin is expanded, water is pumped through the line 41 and thevalve 4%) to the injection point 3%) to determine the acceptance offluid through the leak. After this is determined, a predeterminedquantity of the plugging material is mixed and is passed through theline 41 and the valve to the injection point 30. After sumcient materialhas been placed in the joint to seal the leak, the valve 40 is shiftedby hydraulic pressure on a the exposed face of the piston 47 and thiscauses the flow from line 41 to be Wasted through outlet line 4-3. Thisholds the plugging material behind the injection point until thematerial sets.

After the material has set, the skin 31 is deflated by permitting theair to escape through the pipe 34. The valve 4% is then returned to itsoriginal position by releasing the hydraulic pressure in line 42 andwater is forced through line 41 to the valve it to blow the in jectionmeans clean of the plugging material. The packer is then ready to bemoved along the pipe to detect and seal the next leak.

The foregoing detailed description is given for clearness ofunderstanding and no unnecessary limitations should be understoodtherefrom, as modifications will be obvious to those skilled in the art.

We claim:

1. A method for internally sealing a pipe leak by means of a packercomprising moving the packer along the interior of the pipe until atarget located a fixed distance ahead of the packer is at the leak;advancing the packer by an amount equal to said fixed distance to placethe packer at the leak; isolating the leak from the remainder of thepipe; and injecting a settable material into the leak from the interiorof the packer.

2. The method of detecting the location of a fluid ina i t filtrationfault in a subterranean pipe line extending generally parallel to theground surface comprising the steps of drawing along the pipe linebetween two axially spaced access openings a sensing unit adapted formovement parallel to the axis of the pipe line and provided with atarget disposed a known distance therefrom; receiving signals from thesensing unit indicative of the conditions existing in the pipe line; andmeasuring the distance from the target to a selected reference point.

3. The method of detecting the location of a fluid infiltration fault ina subterranean pipe line extending generally parallel to the groundsurface comprising the steps of drawing along the pipe line between twoaxially spaced access openings a sensing unit adapted for movementparallel to the axis of the pipe line and'provided with a targetdisposed a known distance therefrom; receiving signals from the sensingunit indicative of the conditions existing in the pipe line; anddetermining the target position at a time when the target is judged tobe adjacent a fluid infiltration fault.

4. A method for internally sealing a pipe leak with a packer having atelevision camera comprising, moving the packer along the interior ofthe pipe until a leak is detected by the camera and a target located afixed distance ahead of the'packer is at the leak, advancing the packerby an amount equal to said fixed distance to place the packer at theleak, isolating the leak from the remainder of the pipe, and injecting asettable material into the leak from the packer.

5. A method for internally sealing a leak in a pipe with a packer.having a television camera comprising: moving the packer along withinthe pipe until a leak is detected by the camera and a target a fixeddistance from the packer is at the leak, advancing the packer'by anamount equal to said fixed distance to locateinjection means on thepacker at the leak, expanding a skin substantially surrounding thepacker into contact with the pipe on either side of the leak, passing asettable material through the injection means to plug the leak, andafter said material has set contracting the skin and removing thepacker,

6. The method of detecting, locating and injecting a settable sealantinto a fluid infiltration fault in a pipe line extending generallyparallel to the ground surface comprising the steps of drawing along thelength of the pipe line between two axially spaced access openings atelevision camera unit having a television camera disposed with itsoptical axis extending generally along the axis of the pipe line andhaving a target disposed a known fixed distance from the televisioncamera in the field of view thereof to be imaged by the televisioncamera along with the image of the pipe line; observing the imageproduced by the television camera at a television monitor located abovethe ground surface and receiving image producing signals from thetelevision camera to detect the conditions existing in the interior ofthe pipe line; locating the fault site with the aid of the target;aligning therewith injection means for supplying sealant; and injectingsealant under pressure into the fault site.

7. The method of detecting, locating and injecting a settable sealantinto a fluid infiltration fault in a pipe line extending generallyparallel to the ground surface comprising the steps of drawing along thelength of the pipe line between two axially spaced access openings atelevision camera unit having a television camera disposed with itsoptical axis extending generally along the axis of the pipe line andhaving a target disposed a known fixed distance from the televisioncamera in the field of view thereof to be imaged by the televisioncamera along with the image of the pipe line; observing the imageproduced by the television camera at a television monitor located abovethe ground surface and receiving image producing signals from thetelevision camera to detect the conditions existing in the interior ofthe pipe line; locating the fault site with the aid of the target;aligning therewith injectionmeans for supplying sealant to the faultsite from the interior of the pipe line; and injecting sealant underpressure into the fault site.

8. The method of detecting, locating and injecting a settable sealantinto a fluid infiltration fault in a pipe line extending generallyparallel to the ground surface comprising the steps of drawing along thelength of the pipe line between two axially spaced access openings atelevision camera unit having a television camera disposed with itsoptical axis extending generally along the axis of the pipe line andhaving a target disposed a known fixed distance from the televisioncamera in the field of view thereof to be imaged by the televisioncamera along with the image of the pipe line; observing the imageproduced by the television camera at a television monitor located abovethe ground surface and receiving image producing signals from thetelevision camera to detect the conditions existing in the interior ofthe pipe line; locating the fault in the pipe line With the aid of thetarget; aligning therewith injection means for supplying sealant;isolating the fault from the remainder of the pipe line; and injectingsealant under pressure into the fault site.

9. The method of detecting, locating and injecting a settable sealantinto a fluid infiltration fault in a pipe line extending generallyparallel to the ground surface comprising the steps of drawing along thelength of the pipe line between two axially spaced access openings atelevision camera unit having a television camera disposed with itsoptical axis extending generally along the axis of the pipe line andhaving a target disposed a known fixed distance from the televisioncamera in the field of view thereof to be imaged by the televisioncamera along with the image of the pipe line; observing the imageproduced by the television camera at a television monitor located abovethe ground surface and receiving image producing signals from the thetelevision camera to detect the conditions existing in the interior ofthe pipe line; locating the fault in the pipe line with the aid of thetarget; aligning therewith injection means for supplying sealant;isolating the fault inwardly of the fault site by expanding aninflatable element into engagement with the interior of the pipe line;and injecting sealant under pressure into the fault site. 7

10. The method of detecting, locating and injecting a settable sealantinto a fluid infiltration fault in a pipe line extending generallyparallel to the ground surface comprising the steps of drawing along thelength of the pipe line between two axially spaced access openings atelevision camera unit having a television camera disposed with itsoptical axis extending generally along the axis of the pipe line andhaving a target disposed a known fixed distance from the televisioncamera in the field of view thereof to be imaged by the televisioncamera along with the image of the pipe line; observing the imageproduced by the television camera at a television monitor lo cated abovethe ground surface and receiving image producing signals from thetelevision camera to detect the conditions existing in the interior ofthe pipe line; locating the fault in the pipe line with the aid of thetarget; aligning therewith injection means for supplying sealant to thefault site from the interior of the pipe line; isolating the faultinwardly of the fault site by expanding an inflatable element intoengagement with the interior of the pipe line; and injecting sealantunder pressure into the fault site.

11. The method of detecting the location of any fluid infiltrationfaults and the like in subterranean pipe lines extending generallyparallel to the ground surface comprising the steps of drawing along thelength of a subterranean pipe line between two axially spaced accessopenings at the opposite ends of the pipe line a television camera unithaving a television camera disposed with its optical axis extendinggenerally along the axis of the pipe line and having a target disposed aknown fixed distance from the television camera in the field of Viewthereof to be imaged by the television camera along with the image ofthe pipe line interior, observing the image produced by the televisioncamera at a television monitor located above the ground surface andreceiving image producing signals from the television camera to detectthe conditions existing in the pipe line adjacent the target, and whenthe target is adjacent a fluid infiltration fault establishing thelocation of the fault site by taking the target position measurement.

12. The method of detecting the location of any fluid infiltrationfaults and the like in subterranean pipe lines extending generallyparallel to the ground surface com prising the steps of drawing alongthe length of a subterranean pipe line between two axially spaced accessopenings a television camera unit having a television camera disposedwith its optical axis extending generally along the axis of the pipeline and having a target disposed a known fixed distance from thetelevision camera in the field of view thereof to be imaged by thetelevision camera along with the image of the pipe line interior,observing the image produced by the television camera at a televisionmonitor located above the ground surface and receiving image producingsignals from the television camera to detect the conditions existing inthe pipe line adjacent the target, and determining the target positionwhen the target is adjacent a fluid infiltration fault.

References Cited by the Examiner UNITED STATES PATENTS 2,894,539 7/59Cook 138-97 2,971,259 2/61 Hahnau 1786 DAVID G. REDINBAUGH, PrimaryExaminer.

1. A METHOD FOR INTERNALLY SEALING A PIPE LEAK BY MEANS OF A PACKERCOMPRISING MOVING THE PACKER ALONG THE INTERIOR OF THE PIPE UNTIL ATARGET LOCATED A FIXED DISTANCE AHEAD OF THE PACKER IS AT THE LEAK;ADVANCING THE PACKER BY AN AMOUNT EQUAL TO SAID FIXED DISTANCE TO PLACETHE PACKER AT THE LEAK; ISOLATING THE LEAK FROM THE REMAINDER OF THEPIPE; AND INJECTING A SETTABLE MATERIAL INTO THE LEAK FROM THE INTERIOROF THE PACKER.